1. Field of the Invention
The present invention relates to an exposure head for forming a latent image with a multi-exposure method on a photoreceptor in an electrophotographic printer or copy machine.
2. Description of the Related Art
In the field of image formation devices, various proposals have been made in adopting an organic EL as the light source for exposing the photoreceptor (for example, c.f. Japanese Patent Laid-Open Publication No. H9-226171).
FIG. 17 is a diagram exemplifying the configuration of an organic EL array print head adopting an organic EL as the light source. As shown in FIG. 17, arranged on a chip-on-board (hereinafter referred to as “COB”) substrate 100 are an organic EL array substrate 300 having an organic EL array 200, and a plurality of driver ICs 400 for controlling the emission of each organic EL. The COB substrate 100 and driver IC 400 are electrically connected with a bonding wire 500, and the driver IC 400 and organic EL array substrate 300 are also electrically connected with the bonding wire 500. As described above, as a result of using an organic EL as the light source for exposing the photoreceptor, a single organic EL array substrate 300 can be manufactured collectively, and cost reduction and high densification can be sought in comparison to conventional mounting methods of arranging a plurality of LED chips on a straight line.
Nevertheless, when the organic EL array substrate and plurality of driver ICs are arranged planarly on the COB substrate as described above, there is an inconvenience in that the mounting area will increase, and the COB substrate will become enlarged. Further, a wire bonding process will be required for electrically connecting the organic EL array substrate and the respective driver ICs, and there is an inconvenience in that the wiring between the respective terminals to be wire-bonded to the respective organic EL light emitting units in the organic EL substrate will become complicated and complex. Such inconveniences are especially noticeable when arranging a plurality of rows of organic EL light emitting units against the vertical scanning direction and performing multi-exposure thereto.